TY - JOUR
T1 - Autoantibodies from Single Circulating Plasmablasts React with Citrullinated Antigens and Porphyromonas gingivalis in Rheumatoid Arthritis
AU - Li, Song
AU - Yu, Yangsheng
AU - Yue, Yinshi
AU - Liao, Hongyan
AU - Xie, Wanqin
AU - Thai, Jessica
AU - Mikuls, Ted R
AU - Thiele, Geoffrey Milton
AU - Duryee, Michael J.
AU - Sayles, Harlan
AU - Payne, Jeffrey B
AU - Klassen, Lynell Warren
AU - O'Dell, James Robert
AU - Zhang, Zhixin
AU - Su, Kaihong
N1 - Publisher Copyright:
© 2016, American College of Rheumatology.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Objective Anti-citrullinated protein antibodies (ACPAs) are highly specific for rheumatoid arthritis (RA). However, the molecular basis for ACPA production is still unclear. The purpose of this study was to determine if circulating plasmablasts from RA patients produce ACPAs and whether Porphyromonas gingivalis facilitates the generation of ACPAs. Methods Using a single-cell antibody cloning approach, we generated 217 and 110 monoclonal recombinant antibodies from circulating plasmablasts from 7 RA patients and 4 healthy controls, respectively. Antibody reactivity with citrullinated antigens was tested by a second-generation anti-cyclic citrullinated peptide (anti-CCP) kit and by enzyme-linked immunosorbent assays (ELISAs) against citrullinated human antigens. Antibody reactivity with P gingivalis was tested by ELISAs against outer membrane antigens (OMAs) and citrullinated enolase from P gingivalis. Results Approximately 19.5% of plasmablast-derived antibodies from anti-CCP-positive RA patients, but none from 1 anti-CCP-negative RA patient or the healthy controls, specifically recognized citrullinated antigens. The immunoglobulin genes encoding these ACPAs were highly mutated, with increased ratios of replacement mutations to silent mutations, suggesting the involvement of active antigen selection in ACPA generation. Interestingly, 63% of the ACPAs cross-reacted with OMAs and/or citrullinated enolase from P gingivalis. The reactivity of ACPAs against citrullinated proteins from P gingivalis was confirmed by immunoblotting and mass spectrometry. Furthermore, some germline-reverted ACPAs retained their reactivity with P gingivalis antigens but completely lost their reactivity with citrullinated human antigens. Conclusion These results suggest that circulating plasmablasts in RA patients produce ACPAs and that this process may be facilitated by anti-P gingivalis immune responses.
AB - Objective Anti-citrullinated protein antibodies (ACPAs) are highly specific for rheumatoid arthritis (RA). However, the molecular basis for ACPA production is still unclear. The purpose of this study was to determine if circulating plasmablasts from RA patients produce ACPAs and whether Porphyromonas gingivalis facilitates the generation of ACPAs. Methods Using a single-cell antibody cloning approach, we generated 217 and 110 monoclonal recombinant antibodies from circulating plasmablasts from 7 RA patients and 4 healthy controls, respectively. Antibody reactivity with citrullinated antigens was tested by a second-generation anti-cyclic citrullinated peptide (anti-CCP) kit and by enzyme-linked immunosorbent assays (ELISAs) against citrullinated human antigens. Antibody reactivity with P gingivalis was tested by ELISAs against outer membrane antigens (OMAs) and citrullinated enolase from P gingivalis. Results Approximately 19.5% of plasmablast-derived antibodies from anti-CCP-positive RA patients, but none from 1 anti-CCP-negative RA patient or the healthy controls, specifically recognized citrullinated antigens. The immunoglobulin genes encoding these ACPAs were highly mutated, with increased ratios of replacement mutations to silent mutations, suggesting the involvement of active antigen selection in ACPA generation. Interestingly, 63% of the ACPAs cross-reacted with OMAs and/or citrullinated enolase from P gingivalis. The reactivity of ACPAs against citrullinated proteins from P gingivalis was confirmed by immunoblotting and mass spectrometry. Furthermore, some germline-reverted ACPAs retained their reactivity with P gingivalis antigens but completely lost their reactivity with citrullinated human antigens. Conclusion These results suggest that circulating plasmablasts in RA patients produce ACPAs and that this process may be facilitated by anti-P gingivalis immune responses.
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U2 - 10.1002/art.39455
DO - 10.1002/art.39455
M3 - Article
C2 - 26474325
AN - SCOPUS:84963831507
SN - 2326-5191
VL - 68
SP - 614
EP - 626
JO - Arthritis and Rheumatology
JF - Arthritis and Rheumatology
IS - 3
ER -